About WannaCry these days

At the worst, just re-installing. ---> The worst part is just re-installing

Although, I still updated my windows operating system. After all, updating costs less time I think.
　　I read a post on PTT(the most popular BBS site in Taiwan) yesterday. The post said a computer got WannaCry. ---> a computer had WannaCry / a computer was infected with WannaCry

But the user did't have enough money to exchange Bitcoin.  ---> didn't have enough money to exchange for Bitcoins / to buy Bitcoins

So that he wrote an e-mail to WannaCry's mailbox to explain how low his salary is. ---> So he wrote an email .....

Then its service personnel returned "sorry, may we overestimated your salary level, we're gonna decode your files soon, and you don't need to pay any fees."    ---> Then its service personel replied "sorry, maybe we...."
　　So lucky he is! So kind the service personnel is!    ---> this sounds a bit strange in English, it would be better to say  --> He is so lucky! The service personnel are so kind!